Address minor comments

pkg/event/event.go

@@ -44,11 +44,9 @@ func init() {
 	eventToString[Stopped] = "stopped"
 	eventToString[Completed] = "completed"
 
-	stringToEvent[""] = None
-	stringToEvent["none"] = None
-	stringToEvent["started"] = Started
-	stringToEvent["stopped"] = Stopped
-	stringToEvent["completed"] = Completed
+	for k, v := range eventToString {
+		stringToEvent[v] = k
+	}
 }
 
 // New returns the proper Event given a string.

pkg/event/event_test.go

@@ -16,7 +16,7 @@ func TestNew(t *testing.T) {
 		expected    event
 		expectedErr error
 	}{
-		{"", None, nil},
+		{"", None, ErrUnknownEvent},
 		{"NONE", None, nil},
 		{"none", None, nil},
 		{"started", Started, nil},